Progress in small-incision cataract surgery has led to the development of soft, flexible and foldable materials suitable for intraocular lenses. In particular, acrylic materials are desirable because they have a high refractive index and unfold slowly after insertion into an eye. However, when a material with enhanced shape recoverability is used for a lens, the elongation percentage of the lens becomes low. This material is brittle and easily torn when the lens has, for example, a flaw. To insert a lens into an eye through a minimum incision, it is preferable to use a material with a large elongation percentage so that the lens is prevented from cracking and tearing.
One previously proposed intraocular lens material is a polymer obtained by polymerizing polymerizable components including a hydrophilic monomer such as a hydroxyl group-containing alkyl (meth)acrylate, a (meth)acrylamide monomer, or an N-vinyl lactam, and the water absorption percentage of the intraocular lens material is 1.5 to 4.5% by mass (see, for example, PTL 1). This intraocular lens material is excellent in flexibility and has a high refractive index. Therefore, a lens with a reduced thickness can be provided, and the lens in a folded state can be inserted through an incision. Moreover, the intraocular lens material has excellent transparency and can reduce the occurrence of glistening.